Alcohol and Exercise Affect Declining Kidney Function in Healthy Males Regardless of Obesity: A Prospective Cohort Study

RESEARCH ARTICLE Alcohol and Exercise Affect Declining Kidney Function in Healthy Males Regardless of Obesity: A Prospective Cohort Study Eiichiro Kanda1,2☯*, Toshitaka Muneyuki3,4☯, Kaname Suwa5☯, Kei Nakajima6,7☯ a11111 1 Department of Nephrology, Tokyo Kyosai Hospital, Meguro, Tokyo, Japan, 2 Center for life science and bioethics, Tokyo Medical and Dental University, Bunkyo, Tokyo, Japan, 3 Saitama Citizens Medical Center, Saitama, Saitama, Japan, 4 Department of Rehabilitation, Funabashi City Rehabilitation Hospital, Funabashi, Chiba, Japan, 5 Saitama Health Promotion Corporation, Hikigun, Saitama, Japan, 6 Division of Clinical Nutrition, Department of Medical Dietetics, Faculty of Pharmaceutical Sciences, Josai University, Sakado, Saitama, Japan, 7 Department of Metabolism, Kuki General Hospital, Kuki, Saitama, Japan ☯ These authors contributed equally to this work. * OPEN ACCESS Citation: Kanda E, Muneyuki T, Suwa K, Nakajima K (2015) Alcohol and Exercise Affect Declining Kidney Function in Healthy Males Regardless of Obesity: A Prospective Cohort Study. PLoS ONE 10(8): e0134937. doi:10.1371/journal.pone.0134937 Editor: Keitaro Matsuo, Aichi Cancer Center Research Institute, JAPAN Received: January 10, 2015 Abstract Background Although lifestyle is associated with metabolic syndrome and cardiovascular diseases, there has been no sufficient evidence of lifestyles on incident chronic kidney disease (CKD). The purpose of this prospective cohort study is to investigate the effects of lifestyles on kidney function in healthy people. Accepted: July 15, 2015 Published: August 3, 2015 Methods Copyright: © 2015 Kanda et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. A total of 7473 healthy people were enrolled in this Saitama Cardiometabolic Disease and Organ Impairment Study, Japan. Data on alcohol consumption, exercise frequency, and sleep duration were collected. The outcome event was incident CKD or decrease in estimated glomerular filtration rate (eGFR) by >25% in 3 years. Data Availability Statement: All relevant data is available from the Saitama Health Promotion Corporation, a third-party. The authors confirm that all interested researchers will be able to access this data by contacting the Saitama Health Promotion Corporation's Sales Promotion Division via their website (http://www.saitama-kenkou.or.jp/customer. php). Funding: Saitama Health Promotion Corporation provided support in the form of salaries for one author [KS], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific Results Subjects were classified into four groups according to body mass index and gender. Mean ± standard deviation of age was 38.8±10.5 years; eGFR, 78.1±15.2 ml/min/1.73m2. In the male groups, multivariate logistic regression models showed that the outcome events were associated with a small amount of alcohol consumed (20 to 140g of alcohol/week) (ref. more than 140g of alcohol/week); non-obese male, adjusted odds ratio 1.366 (95% confidence interval, 1.086, 1.718); obese male (body mass index 25), 1.634 (1.160, 2.302); and with frequent exercise (twice a week or more) (ref. no exercise); non-obese male, 1.417 (1.144, 1.754); obese male, 1.842 (1.317, 2.577). Sleep duration was not associated with the outcome events. PLOS ONE | DOI:10.1371/journal.pone.0134937 August 3, 2015 1 / 11 Lifestyle and Kidney Function roles of the authors are articulated in the ‘author contributions’ section. Competing Interests: The authors have no competing interests. Since 1997, Saitama Health Promotion Corporation, a public interest corporation, supported the health of individuals, including children and adolescents, living or working in Saitama prefecture, primarily by carrying out various types of medical checkups. Only KS was employed by Saitama Health Promotion Corporation. He had no competing interests in this study. The other authors, EK, TM, and KN, declare that they have no competing interests. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. Conclusion These findings suggest that, regardless of obesity, a small amount of alcohol consumed and high exercise frequency were associated with the increased risk of loss of kidney function in the male groups. Introduction It has been reported that in chronic kidney disease (CKD) patients some lifestyles have combined effects on the life prognosis of these patients [1]. Moreover, lifestyles are related to metabolic syndrome, which is a factor related not only to diabetes mellitus (DM) and cardiovascular diseases (CVDs) but also to incident CKD [2]. However, there has been no sufficient evidence of the effects of lifestyles on incident CKD. The relationship between an amount of alcohol consumed and incident CKD has been investigated in longitudinal observational studies. In a community-based followed-up study carried out in Japan, the risk of incident CKD decreased in the group with alcohol consumption of less than 20 g/day but did not significantly decrease in the group with alcohol consumption of 20 g/day or more compared with that in the non-alcohol-consuming group [3]. According to the Australian population-representative study (AusDiab study), the risk of incident CKD are reduced in the group with a large amount of alcohol consumed [4]. In a systematic review, improvements in aerobic capability, muscular function, cardiovascular function, walking capacity, and health-related quality of life were reported as the effects of exercise in CKD patients [5]. The protective effects of exercise on glomerular filtration rate (GFR) were not demonstrated in interventional studies on CKD patients owing to the small sample size [6, 7]. In a cross-sectional study conducted by the National Health and Nutrition Examination Survey (NHANES), the hours of sleep are shorter in the patients with CKD stages 1 and 2 than in those with CKD stages 3 and 4 [8]. As far as we investigated, there have been no longitudinal studies clarifying the relationship between hours of sleep and incident CKD. Obesity and metabolic syndrome have been reported as risk factors for CKD [9]. The gender difference in the relationship between body mass index (BMI) and CKD has been reported [10]. Obese females have a higher risk of CKD than non-obese females, and there is no difference in the risk of CKD between obese and non-obese males. To prevent metabolic syndrome and DM, exercise is often recommended for obese people to lose weight. On the other hand, non-obese people do not need to lose weight. When lifestyle guidance is provided to healthy people in order to prevent CKD, the content of the guidance is determined by their gender and obesity. (...truncated)